/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.startup;

import java.io.File;
import java.util.Enumeration;

import org.apache.catalina.Context;
import org.apache.catalina.Host;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleEvent;
import org.apache.catalina.LifecycleListener;
import org.apache.catalina.util.StringManager;

/**
 * Startup event listener for a <b>Host</b> that configures Contexts (web
 * applications) for all defined "users" who have a web application in a
 * directory with the specified name in their home directories. The context path
 * of each deployed application will be set to <code>~xxxxx</code>, where xxxxx
 * is the username of the owning user for that web application
 * 
 * @author Craig R. McClanahan
 * @version $Id: UserConfig.java 939353 2010-04-29 15:50:43Z kkolinko $
 */

public final class UserConfig implements LifecycleListener {

	private static org.apache.juli.logging.Log log = org.apache.juli.logging.LogFactory
			.getLog(UserConfig.class);

	// ----------------------------------------------------- Instance Variables

	/**
	 * The Java class name of the Context configuration class we should use.
	 */
	private String configClass = "org.apache.catalina.startup.ContextConfig";

	/**
	 * The Java class name of the Context implementation we should use.
	 */
	private String contextClass = "org.apache.catalina.core.StandardContext";

	/**
	 * The directory name to be searched for within each user home directory.
	 */
	private String directoryName = "public_html";

	/**
	 * The base directory containing user home directories.
	 */
	private String homeBase = null;

	/**
	 * The Host we are associated with.
	 */
	private Host host = null;

	/**
	 * The string resources for this package.
	 */
	private static final StringManager sm = StringManager
			.getManager(Constants.Package);

	/**
	 * The Java class name of the user database class we should use.
	 */
	private String userClass = "org.apache.catalina.startup.PasswdUserDatabase";

	// ------------------------------------------------------------- Properties

	/**
	 * Return the Context configuration class name.
	 */
	public String getConfigClass() {

		return (this.configClass);

	}

	/**
	 * Set the Context configuration class name.
	 * 
	 * @param configClass
	 *            The new Context configuration class name.
	 */
	public void setConfigClass(String configClass) {

		this.configClass = configClass;

	}

	/**
	 * Return the Context implementation class name.
	 */
	public String getContextClass() {

		return (this.contextClass);

	}

	/**
	 * Set the Context implementation class name.
	 * 
	 * @param contextClass
	 *            The new Context implementation class name.
	 */
	public void setContextClass(String contextClass) {

		this.contextClass = contextClass;

	}

	/**
	 * Return the directory name for user web applications.
	 */
	public String getDirectoryName() {

		return (this.directoryName);

	}

	/**
	 * Set the directory name for user web applications.
	 * 
	 * @param directoryName
	 *            The new directory name
	 */
	public void setDirectoryName(String directoryName) {

		this.directoryName = directoryName;

	}

	/**
	 * Return the base directory containing user home directories.
	 */
	public String getHomeBase() {

		return (this.homeBase);

	}

	/**
	 * Set the base directory containing user home directories.
	 * 
	 * @param homeBase
	 *            The new base directory
	 */
	public void setHomeBase(String homeBase) {

		this.homeBase = homeBase;

	}

	/**
	 * Return the user database class name for this component.
	 */
	public String getUserClass() {

		return (this.userClass);

	}

	/**
	 * Set the user database class name for this component.
	 */
	public void setUserClass(String userClass) {

		this.userClass = userClass;

	}

	// --------------------------------------------------------- Public Methods

	/**
	 * Process the START event for an associated Host.
	 * 
	 * @param event
	 *            The lifecycle event that has occurred
	 */
	public void lifecycleEvent(LifecycleEvent event) {

		// Identify the host we are associated with
		try {
			host = (Host) event.getLifecycle();
		} catch (ClassCastException e) {
			log.error(sm.getString("hostConfig.cce", event.getLifecycle()), e);
			return;
		}

		// Process the event that has occurred
		if (event.getType().equals(Lifecycle.START_EVENT))
			start();
		else if (event.getType().equals(Lifecycle.STOP_EVENT))
			stop();

	}

	// -------------------------------------------------------- Private Methods

	/**
	 * Deploy a web application for any user who has a web application present
	 * in a directory with a specified name within their home directory.
	 */
	private void deploy() {

		if (host.getLogger().isDebugEnabled())
			host.getLogger().debug(sm.getString("userConfig.deploying"));

		// Load the user database object for this host
		UserDatabase database = null;
		try {
			Class clazz = Class.forName(userClass);
			database = (UserDatabase) clazz.newInstance();
			database.setUserConfig(this);
		} catch (Exception e) {
			host.getLogger().error(sm.getString("userConfig.database"), e);
			return;
		}

		// Deploy the web application (if any) for each defined user
		Enumeration users = database.getUsers();
		while (users.hasMoreElements()) {
			String user = (String) users.nextElement();
			String home = database.getHome(user);
			deploy(user, home);
		}

	}

	/**
	 * Deploy a web application for the specified user if they have such an
	 * application in the defined directory within their home directory.
	 * 
	 * @param user
	 *            Username owning the application to be deployed
	 * @param home
	 *            Home directory of this user
	 */
	private void deploy(String user, String home) {

		// Does this user have a web application to be deployed?
		String contextPath = "/~" + user;
		if (host.findChild(contextPath) != null)
			return;
		File app = new File(home, directoryName);
		if (!app.exists() || !app.isDirectory())
			return;
		/*
		 * File dd = new File(app, "/WEB-INF/web.xml"); if (!dd.exists() ||
		 * !dd.isFile() || !dd.canRead()) return;
		 */
		host.getLogger().info(sm.getString("userConfig.deploy", user));

		// Deploy the web application for this user
		try {
			Class clazz = Class.forName(contextClass);
			Context context = (Context) clazz.newInstance();
			context.setPath(contextPath);
			context.setDocBase(app.toString());
			if (context instanceof Lifecycle) {
				clazz = Class.forName(configClass);
				LifecycleListener listener = (LifecycleListener) clazz
						.newInstance();
				((Lifecycle) context).addLifecycleListener(listener);
			}
			host.addChild(context);
		} catch (Exception e) {
			host.getLogger().error(sm.getString("userConfig.error", user), e);
		}

	}

	/**
	 * Process a "start" event for this Host.
	 */
	private void start() {

		if (host.getLogger().isDebugEnabled())
			host.getLogger().debug(sm.getString("userConfig.start"));

		deploy();

	}

	/**
	 * Process a "stop" event for this Host.
	 */
	private void stop() {

		if (host.getLogger().isDebugEnabled())
			host.getLogger().debug(sm.getString("userConfig.stop"));

	}

}
